Sage is an open source programming language created in 2005.
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SageMath (previously Sage or SAGE, "System for Algebra and Geometry Experimentation") is a mathematical software with features covering many aspects of mathematics, including algebra, combinatorics, numerical mathematics, number theory, and calculus. The first version of SageMath was released on 24 February 2005 as free and open-source software under the terms of the GNU General Public License version 2, with the initial goals of creating an "open source alternative to Magma, Maple, Mathematica, and MATLAB". The originator and leader of the SageMath project, William Stein, is a mathematician at the University of Washington. Read more on Wikipedia...
print("Hello, world!")# -*- coding: utf-8 -*-
#
# Funciones en Python/Sage para el trabajo con polinomios con una
# incógnita (x).
#
# Copyright (C) 2014-2015, David Abián <davidabian [at] davidabian.com>
#
# This program is free software: you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the Free
# Software Foundation, either version 3 of the License, or (at your option)
# any later version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
# FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
# more details.
#
# You should have received a copy of the GNU General Public License along with
# this program. If not, see <http://www.gnu.org/licenses/>.
def pols (grado=-1, K=GF(2), mostrar=False):
"""Devuelve la lista de polinomios constantes y no constantes de
coeficientes mónicos y grado igual o menor que el especificado.
Si el grado indicado no es válido, devuelve una lista vacía.
"""
lpols = []
if not grado.is_integer():
grado = grado.round()
if grado >= 0:
var('x')
xs = vector([(x^i) for i in range(grado+1)])
V = VectorSpace(K,grado+1)
lpols = [cs*xs for cs in V]
if mostrar:
for pol in lpols:
print pol
return lpols
def polsNoCtes (grado=-1, K=GF(2), mostrar=False):
"""Devuelve la lista de polinomios no constantes de coeficientes mónicos y
grado igual o menor que el especificado.
Si el grado indicado no es válido, devuelve una lista vacía.
"""
lpols = []
if not grado.is_integer():
grado = grado.round()
if grado >= 0:
var('x')
xs = vector([(x^i) for i in range(grado+1)])
for cs in K^(grado+1):
if cs[:grado] != vector(grado*[0]): # no constantes
lpols += [cs*xs]
if mostrar:
for pol in lpols:
print pol
return lpols
def polsMismoGrado (grado=-1, K=GF(2), mostrar=False):
"""Devuelve la lista de polinomios de coeficientes mónicos del grado
especificado.
Si el grado indicado no es válido, devuelve una lista vacía.
"""
lpols = []
if not grado.is_integer():
grado = grado.round()
if grado >= 0:
var('x')
xs = vector([(x^(grado-i)) for i in [0..grado]])
for cs in K^(grado+1):
if cs[0] != 0: # polinomios del mismo grado
lpols += [cs*xs]
if mostrar:
for pol in lpols:
print pol
return lpols
def excluirReducibles (lpols=[], mostrar=False):
"""Filtra una lista dada de polinomios de coeficientes mónicos y devuelve
aquellos irreducibles.
"""
var('x')
irreds = []
for p in lpols:
fp = (p.factor_list())
if len(fp) == 1 and fp[0][1] == 1:
irreds += [p]
if mostrar:
for pol in irreds:
print pol
return irreds
def vecPol (vec=random_vector(GF(2),0)):
"""Transforma los coeficientes dados en forma de vector en el polinomio
que representan.
Por ejemplo, con vecPol(vector([1,0,3,1])) se obtiene x³ + 3*x + 1.
Para la función opuesta, véase polVec().
"""
var('x')
xs = vector([x^(len(vec)-1-i) for i in range(len(vec))])
return vec*xs
def polVec (p=None):
"""Devuelve el vector de coeficientes del polinomio dado que acompañan a la
incógnita x, de mayor a menor grado.
Por ejemplo, con polVec(x^3 + 3*x + 1) se obtiene el vector (1, 0, 3, 1).
Para la función opuesta, véase vecPol().
"""
cs = []
if p != None:
var('x')
p(x) = p
for i in [0..p(x).degree(x)]:
cs.append(p(x).coefficient(x,i))
cs = list(reversed(cs))
return vector(cs)
def completar2 (p=0):
"""Aplica el método de completar cuadrados en parábolas al polinomio dado de
grado 2 y lo devuelve en su nueva forma.
Si el polinomio dado no es válido, devuelve 0.
Por ejemplo, con complCuad(3*x^2 + 12*x + 5) se obtiene 3*(x + 2)^2 - 7.
"""
var('x')
p(x) = p.expand()
if p(x).degree(x) != 2:
p(x) = 0
else:
cs = polVec(p(x))
p(x) = cs[0]*(x+(cs[1]/(2*cs[0])))^2+(4*cs[0]*cs[2]-cs[1]^2)/(4*cs[0])
return p(x)
sage: E2 = EllipticCurve(CC, [0,0,-2,1,1])
sage: E2
Elliptic Curve defined by y^2 + (-2.00000000000000)*y =
x^3 + 1.00000000000000*x + 1.00000000000000 over
Complex Field with 53 bits of precision
sage: E2.j_invariant()
61.7142857142857| Feature | Supported | Example | Token |
|---|---|---|---|
| Comments | ✓ | # A comment | |
| Line Comments | ✓ | # A comment | # |
| Case Insensitive Identifiers | X | ||
| Semantic Indentation | X |